The Organization of Petroleum Exporting Countries said its proven crude oil reserves rose 4 percent last year, led by gains in Venezuela.

The total amount of crude under OPEC territory advanced to 1.064 trillion barrels in 2009, the group said in its Annual Statistical Bulletintoday. This follows an increase of 7.9 percent in 2008, the biggest in 20 years. Venezuela’s share surged 23 percent to 211.2 billion barrels.

State oil company Petroleos de Venezuela SA, known as PDVSA, has tapped tar-like crude in the Orinoco Belt to swell supplies as output in other parts of the country dwindle. The Orinoco Belt is one of the world’s biggest oil deposits, with 513 billion barrels that may be recovered using current technology, according to the U.S. Geological Survey.

Reserves declined in Iran by 0.4 percent to 137 billion barrels, and in Qatar by 0.1 percent to 25.38 billion barrels, according to the report. Reserves in Saudi Arabia, which holds the world’s largest, grew 0.2 percent to 264.59 billion barrels.

OPEC said that its share of global reserves advanced 0.6 percent to 79.6 percent.